Merge branch 'BUG_ON' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus
* 'BUG_ON' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
Remove MAYBE_BUILD_BUG_ON
BUILD_BUG_ON: make it handle more cases
diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index a3b148a..0b84c61 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -249,7 +249,7 @@
((1 << ZONES_SHIFT) - 1);
if (__builtin_constant_p(bit))
- MAYBE_BUILD_BUG_ON((GFP_ZONE_BAD >> bit) & 1);
+ BUILD_BUG_ON((GFP_ZONE_BAD >> bit) & 1);
else {
#ifdef CONFIG_DEBUG_VM
BUG_ON((GFP_ZONE_BAD >> bit) & 1);
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index d07d805..e2f4d6a 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -575,12 +575,6 @@
char _f[20-2*sizeof(long)-sizeof(int)]; /* Padding: libc5 uses this.. */
};
-/* Force a compilation error if condition is true */
-#define BUILD_BUG_ON(condition) ((void)BUILD_BUG_ON_ZERO(condition))
-
-/* Force a compilation error if condition is constant and true */
-#define MAYBE_BUILD_BUG_ON(cond) ((void)sizeof(char[1 - 2 * !!(cond)]))
-
/* Force a compilation error if a constant expression is not a power of 2 */
#define BUILD_BUG_ON_NOT_POWER_OF_2(n) \
BUILD_BUG_ON((n) == 0 || (((n) & ((n) - 1)) != 0))
@@ -592,6 +586,32 @@
#define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); }))
#define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); }))
+/**
+ * BUILD_BUG_ON - break compile if a condition is true.
+ * @cond: the condition which the compiler should know is false.
+ *
+ * If you have some code which relies on certain constants being equal, or
+ * other compile-time-evaluated condition, you should use BUILD_BUG_ON to
+ * detect if someone changes it.
+ *
+ * The implementation uses gcc's reluctance to create a negative array, but
+ * gcc (as of 4.4) only emits that error for obvious cases (eg. not arguments
+ * to inline functions). So as a fallback we use the optimizer; if it can't
+ * prove the condition is false, it will cause a link error on the undefined
+ * "__build_bug_on_failed". This error message can be harder to track down
+ * though, hence the two different methods.
+ */
+#ifndef __OPTIMIZE__
+#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
+#else
+extern int __build_bug_on_failed;
+#define BUILD_BUG_ON(condition) \
+ do { \
+ ((void)sizeof(char[1 - 2*!!(condition)])); \
+ if (condition) __build_bug_on_failed = 1; \
+ } while(0)
+#endif
+
/* Trap pasters of __FUNCTION__ at compile-time */
#define __FUNCTION__ (__func__)
diff --git a/include/linux/kmemcheck.h b/include/linux/kmemcheck.h
index 08d7dc4..39f8453 100644
--- a/include/linux/kmemcheck.h
+++ b/include/linux/kmemcheck.h
@@ -76,7 +76,7 @@
\
_n = (long) &((ptr)->name##_end) \
- (long) &((ptr)->name##_begin); \
- MAYBE_BUILD_BUG_ON(_n < 0); \
+ BUILD_BUG_ON(_n < 0); \
\
kmemcheck_mark_initialized(&((ptr)->name##_begin), _n); \
} while (0)
diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
index 0093dd7..800617b 100644
--- a/include/linux/virtio_config.h
+++ b/include/linux/virtio_config.h
@@ -109,7 +109,10 @@
unsigned int fbit)
{
/* Did you forget to fix assumptions on max features? */
- MAYBE_BUILD_BUG_ON(fbit >= 32);
+ if (__builtin_constant_p(fbit))
+ BUILD_BUG_ON(fbit >= 32);
+ else
+ BUG_ON(fbit >= 32);
if (fbit < VIRTIO_TRANSPORT_F_START)
virtio_check_driver_offered_feature(vdev, fbit);